1. Field of the Invention
This invention generally relates to paper board containers and more particularly this invention relates to leak proof paperboard containers examples of which are disposable containers adapted for distribution of milk and other dairy products.
2. Description of the Prior Art
Over the past two decades the paperboard container industry has seen much development and rapid change. Developments in the milk carton and dairy product container industry have been in the forefront. Historically, paperboard containers were adapted for fluids by applying paraffin to the paperboard carton as a coating. As improved methods for use of plastic developed, the container industry saw the marriage of plastic and paper replacing the paraffin coating technique as a means for creating a liquid-tight carton.
Paralleling developments relating to carton material have been numerous improvements and innovations with respect to carton configuration and design. The milk packaging industry for example has seen numerous cartons of various shapes and sizes come and go. Because of its functional qualities, however, the gable top pour spout container has grown steadily in popularity and now dominates the milk packaging industry. The two most notable functional qualities of the gable top carton are the ease with which the pour spout can be folded into its pouring position and the effectiveness of the pour spout as a means for pouring liquid from the carton.
There have been several improvements in the gable top carton over the past decade including variations in the scoring pattern and advancements in folding and sealing techniques.
Despite these improvements the gable top carton, due to its peaked top closure, and the consequent inability to stack one such carton atop another has always posed shipping and display problems. Because of its physical shape the gable top carton gives rise to a substantial loss of space economy during shipping and while on display. The awkward stacking characteristics of the gable top carton also burden the consumer both while shopping and subsequently during storage prior to use in the home refrigerator.
There have been several attempts to obviate this basic shortcoming by the creation of cartons having squared or flat tops. Early square top configurations employed peculiar pouring orifices which in most cases were complex and never achieved wide acceptance. One such flat top paper carton is illustrated in U.S. Pat. No. 2,926,832 -- Negoro. There were also attempts to create square top cartons having fold out pour spouts as for example U.S. Pat. No. 2,337,730 Berch and U.S. Pat. No. 3,081,927 Hayhurst. These and other flat top fluid containers have not been acceptable due both to the difficulty and cost of creating such containers and to functional inadequacies of such containers.
At the present time there is no carton which overcomes the stacking drawbacks of the gable top container while preserving the beneficial characteristics and widely accepted pour spout configuration of that carton.
The present invention obviates the deficiencies of the prior art including the above noted problems of the widely accepted gable top carton by providing a new carton blank uniquely scored and a method of folding the carton blank to create a liquid-tight flat top container having a pour spout identical to that of the conventional gable top container.